Go to "My Account"
Click the "Edit" tab
Change your username in the "Username" field to the desired name.
Submit the changes.
Please be advised that the new username will not take affect if that username has already been taken by another user.
To ensure that the username has been changed, click on the "Edit" tab again.
Check to ensure that your new username is listed in the "Username" field.
If the new username is not listed in the "Username" field, that username is already taken and you must either keep your old username or choose a different one.
Remember to repeat the double check any time you choose a new username, and please note that users wishing to access your profile via typing in the address must use your original username.